A developing trend in circuit and display technology involves the implementation of organic electronic and opto-electronic devices, which provide low cost, high performance alternatives to silicon electronic devices. One such organic device is the organic light emitting diode (OLED). OLED's are solid-state semiconductor devices, which implement organic semiconductor layers to convert electrical energy into light. Generally, OLEDs are fabricated by disposing multiple layers of organic thin films between two conductors or electrodes. The electrode layers and the organic layers are generally disposed between two substrates, such as glass or plastic. The OLEDs operate by accepting charge carriers of opposite polarities, electrons and holes, from the electrodes. An externally applied voltage drives the charge carriers into the recombination region to produce light emissions. Unlike many silicon based devices, OLEDs can be processed using low cost, large area thin film deposition processes which allow for the fabrication of ultra-thin, light weight lighting displays. Significant developments have been made in providing general area lighting implementing OLEDs.
Conventional OLED devices may implement top and bottom glass substrates. Advantageously, glass substrates generally provide adequate hermeticity to seal the device from exposure to moisture and oxygen that is present in the atmosphere. Disadvantageously, glass substrates are thick, heavy and relatively fragile. Providing reliable electrical contacts to organic thin films is made more difficult when the devices are exposed to air and water, which can degrade their electronic properties rapidly.
Another example organic electronic device is an organic photovoltaic (OPV) device. OPVs are solid-state semiconductor devices that implement organic semiconductor layers to convert light into electrical energy. Disadvantageously, OPVs may also be susceptible to the degradation, durability and manufacturability issues discussed above with respect to the OLEDs.
To provide more durable and more easily manufacturable devices, the organic electronic devices may be fabricated on a flexible base material such as transparent, polymeric films or metal foils. Polymeric films coated with ultra-high barrier layers and metal foils generally provide hermetically acceptable materials on which to build the organic electronic devices and which may be implemented in roll-to-roll manufacturing processes. While the metal foils and the ultra-high barrier coated polymeric films generally provide sufficient protection from moisture and oxygen on the top and bottom surfaces of the organic electronic device, the edges of the device may still be susceptible to moisture and oxygen. This may be especially true in roll-to-roll manufacturing systems. Accordingly, there is continued need for organic electronic devices, which implement flexible substrates and do not suffer from permeation of environmental elements through the edges of the devices.